1. Field
The present disclosure relates to techniques for aggregating one or more loads in a power system in order to provide an energy service. More specifically, the present disclosure relates to desynchronizing the phases of loads with time-varying operating cycles in order to provide more reliable aggregate energy services.
2. Related Art
In traditional electricity markets, economic mechanisms are frequently used to arrive at accurate incentives and to dispatch services. For example, an operator of a power system, such as an independent system operator (ISO), may request bids up to 24 hours in advance of a desired service. In response to the request, one or more suppliers, such as a power plant, may bid to supply power or ancillary services (such as regulation, load following, spinning reserve, non-spinning reserve, replacement reserve and/or other services that help maintain power system stability in response to unanticipated variations in the supply and demand of electricity.). Based on the received bids, the ISO may select or dispatch the services it needs to operate the power system or grid. In the case of contingency services (e.g., spinning reserve), the ISO may dispatch the services and compensate the corresponding suppliers for being available, even if these suppliers are not subsequently required to provide power.
With the deregulation of electricity markets, and the increased integration of communication and control technology in power systems, it is increasingly attractive for flexible electricity consumers (such as individual residences, as well as small and medium-sized businesses, which are henceforth collectively referred to as ‘participants’) to supply energy services to an ISO. For example, residential consumers of electricity can, in principle, provide ancillary services by shifting their consumption of electricity relative to their baseline consumption patterns. Typically, an aggregator in the power system combines and coordinates the supply and/or demand of multiple participants in order for the aggregate energy service to meet the needs of the ISO.
However, the participants may not be able to offer the same quality of service that an aggregator needs to provide to the ISO. For example, it can be difficult to aggregate loads that operate by cycling on/off, such as heating, ventilating and air-conditioning (HVAC) units that are thermostatically controlled. Because of the uncertainty about which loads will currently be ‘on,’ when an aggregator attempts to combine cycling loads to offer an immediate predictable load reduction, there typically is uncertainty about the total demand reduction that can be immediately achieved.
Hence, what is needed is a method and a system that facilitates aggregation of the energy service without the problems listed above.